1. Field of the Invention
This invention is concerned with acidic esters of polyepoxy resins and water reducible coating compositions containing them.
2. Description of the Prior Art
In U.S. Pat. No. 3,730,926, there is disclosed an electrophoretic coating formulation prepared by adducting maleic anhydride with unsaturated fatty acids, hydrolyzing, reacting with epoxy resin, and solubilizing with ammonia or amine. The proportion of epoxy to carboxyl used is low relative to that of the present invention.
Insofar as is now known, it has not been proposed to react a dicarboxylic acid with a diglycidyl ether of a bisphenol and solubilizing with an amine or ammonia, or to prepare water-reducible coating formulations therefrom with a crosslinking agent and a catalyst.